Figure 1

IgG4-related disease (case 6).

Marked lymphoplasmacytic infiltration with dense fibrosis, scattered eosinophils and interspersed reactive lymphoid follicles are shown (A,B) (hematoxylin & eosin). Numerous IgG⁺ (C) and IgG4⁺ (D) cells are present with an IgG4⁺/IgG⁺ cell ratio >40%.